Methods relating to forming interconnects

ABSTRACT

Methods relating to forming interconnects through injection of conductive materials, to fabricating semiconductor component assemblies, and to resulting assemblies. A semiconductor component substrate, such as a semiconductor die or other substrate, has dielectric material disposed on a surface thereof, surrounding but not covering interconnect elements, such as bond pads, on that surface. A second semiconductor component substrate, such as a carrier substrate with interconnect elements such as terminal pads, is adhered to the first semiconductor component substrate, forming a semiconductor package assembly having interconnect voids between the corresponding interconnect elements. A flowable conductive material is then injected into each interconnect void using an injection needle that passes through one of the substrates into the interconnect void, forming a conductive interconnect between the bond pads and terminal pads of the substrates. In another embodiment, a conductive material is preplaced into the interconnect voids and ultrasonically heated to a flowable state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/123,466, filed May 6, 2005, pending, which is a divisional of U.S.patent application Ser. No. 10/667,003, filed Sep. 19, 2003, now U.S.Pat. No. 6,982,191, issued Jan. 3, 2006, the disclosure of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductors and semiconductorpackages. More particularly, but not limited thereto, it relates to theformation of interconnections between semiconductor substrates, such assemiconductor dice and adjacent substrates in a semiconductor assembly.

2. State of the Art

In conventional flip-chip attachment, an array of conductive bumps suchas solder balls is formed on the surface of a semiconductor die, theconductive bumps being used to mechanically and electrically connect thedie to higher-level packaging, such as a carrier substrate in the formof a printed circuit board. The formation of the solder balls may becarried out by a number of different methods. For example, a compositesolder material of tin and lead may be electrodeposited through a maskto produce a desired pattern of solder masses to form bumps, the soldermaterial then being heated to reflow to form solder balls by surfacetension. Another technique is solder paste screening to cover the entirearea of a wafer, the paste again being heated to reflow and form thesolder balls.

U.S. Pat. No. 6,459,150 to Wu et al., issued Oct. 1, 2002, discloses analternative technique for forming solder ball connections. A substrate,such as a die or interposer, includes a number of bond pads. Aperturesare formed through the body of the substrate and each of the bond pads.A second substrate with corresponding bond pads is placed adjoining thefirst substrate and solder is deposited through the apertures. Solderreflow is then conducted to form solder balls that mechanically andelectrically interconnect the substrates, while forming a conductiveplug that passes through the body of the first substrate.

Each of these techniques thus requires solder reflow, typicallyconducted by passing the semiconductor structure through a reflow ovenand subjecting the entire structure to the heat required to inducereflow. Such solder reflow usually involves four well-defined phases:preheat, soak, reflow (spike) and cool. First, in the preheat phase, thesolder is warmed to a temperature that is just below its melting point.For example, for one conventional tin/lead solder composition, thestructure may be heated to about 30° C. below a melting point of 183° C.In the soak phase, flux used to adhere the solder to under-bumpmetallization (UBM) formed on bond pads or redistributed bond pads isactivated to remove any oxide on the metallization and the temperaturesof the substrate and the solder are allowed to become more uniform andstabilized. During this soak period, the temperatures of the solder andthe substrate are nearly constant or may increase slightly, for example,by about 20° C. In the reflow or spike period, the temperature is causedto increase rapidly and exceeds the melting point by between 20° C. and50° C., such that the solder will melt, wet the metalized bond pads andassume a substantially spherical shape from the surface tension of themolten solder. Finally, in the cooling phase the solder balls and thesubstrate are allowed to cool to a temperature well below the meltingpoint of the solder such that the solder balls solidify. In manyinstances, reflow to form the solder balls is followed by a subsequentreflow to connect the semiconductor die to a carrier substrate.Conventional techniques for flip-chip connection of a semiconductor dieto a carrier substrate using solder are thus somewhat time consuming andsubject the entire semiconductor die to elevated temperatures at leastonce for a substantial period of time, potentially subjecting it todamage as well as shortening the life thereof.

Techniques for flip-chip connection of semiconductor dice to carriersubstrates using conductive materials other than solder are also known.For example, conductive or conductor-filled epoxies may be formed intodiscrete conductive elements in the form of columns or pillars and usedto effect such mechanical and electrical connection. However, such anapproach also involves preplacement of “dots” of the epoxy material on asemiconductor die or carrier substrate, assembly of the two electricalcomponents desired to be attached, and then effecting cure of the epoxy.Furthermore, in many instances, it is desirable or even required toprecure the epoxy to a tacky state, a so-called “B-stage,” for ease ofhandling and preliminary adherence of the epoxy to a target surfaceprior to the final cure.

Accordingly, a method to enable flip-chip style attachment of asemiconductor die to a carrier substrate without the need for thetime-consuming process of placing a solder paste or other solder ballprecursor on a substrate followed by heating of the substrate or anassembly of substrates to form solder balls would constitute animprovement in the art, as would semiconductor packages constructedusing such techniques. Additionally, such a method that would eliminateany need to preplace discrete conductive elements prior to assembly of asemiconductor die with another electronic component such as a carriersubstrate would also be desirable.

BRIEF SUMMARY OF THE INVENTION

The present invention, in several embodiments, is directed to methodsrelating to forming conductive interconnects and associated methods forfabricating semiconductor component assemblies. A semiconductorcomponent substrate, such as a semiconductor substrate, an interposer orother carrier substrate, is provided with an array of first interconnectelements, such as bond pads or terminal pads, on a surface thereof. Anelectrically insulative, or dielectric, material element is disposed onat least a portion of the surface to surround, but not cover, the firstinterconnect elements of the array, defining a cavity over eachinterconnect element. A second semiconductor component substrate, whichagain may comprise a semiconductor substrate, an interposer or othercarrier substrate, is provided with an array of second interconnectelements, such as bond pads or terminal pads, located on a surfacethereof in a pattern complementary to the array of first interconnectelements. The first semiconductor component substrate is secured to thesecond semiconductor component substrate with the first interconnectelements and the second interconnect elements mutually aligned and withthe dielectric material providing a standoff therebetween to form asemiconductor component assembly having interconnect voids formedtherein between the first interconnect elements and second interconnectelements.

In one embodiment, a flowable conductive material is then injected intoeach interconnect void using an injection needle that is passed throughone of the semiconductor substrate components into that interconnectvoid to form a conductive interconnect between the aligned first andsecond interconnect elements associated therewith. One of thesemiconductor component substrates may be formed with access holestherethrough associated with interconnect element locations to receivethe injection needle, or the injection needle may be used to perforatethe substrate through which the conductive material is to be injected. Avent hole may also be optionally formed through a semiconductorcomponent substrate to provide an exit for gases from the interconnectvoid during injection of the conductive material.

In another embodiment, a mass of conductive material such as a solderpellet of paste mass may be placed in the cavities in the dielectricmaterial layer prior to placement of the second semiconductor componentsubstrate thereover to form the semiconductor component assembly.Thereafter, an ultrasonic head in contact with the exterior of one ofthe semiconductor component substrates may be used to rapidly heat andmelt the solder in the interconnect voids to form solder balls.

Embodiments of semiconductor component assemblies resulting from use ofthe methods of the present invention are also encompassed by the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which depict the best mode presently known for carryingout the present invention:

FIG. 1 is a side sectional view of one exemplary embodiment of asemiconductor die attached to a carrier substrate during fabrication ofa semiconductor component assembly in accordance with the presentinvention;

FIG. 1A is a side sectional view of a variant of the exemplaryembodiment of FIG. 1;

FIG. 2 is a side sectional view of the embodiment of FIG. 1 depicting aninjection needle inserted into an interconnect void of the semiconductorcomponent assembly to form a conductive interconnect;

FIG. 2A is an enlarged, side sectional view of the tip of the injectionneedle employed in FIG. 2;

FIG. 3 is a side sectional view of the embodiment of FIG. 1, with aconductive interconnect formed in each of the interconnect voids;

FIG. 4 is a side sectional view of a variation of the embodiment of FIG.1; and

FIG. 5 is a side sectional view of another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

As depicted in FIG. 1, a first semiconductor component substrate in theform of semiconductor die 100 includes a plurality of interconnectelements in the form of bond pads 102 located on an active surface 104thereof. Of course, the present invention may also be practiced onwafer-scale semiconductor substrates as partial wafer, multi-diesubstrates. Accordingly, semiconductor die 100 may be taken as arepresentation of any size or type of semiconductor substrate. Bond pads102 may comprise bond pads directly connected to integrated circuitryformed on active surface 104, or redistributed bond pads placed in adesired pattern or array and connected by conductive traces extendingover the active surface 104 from original bond pad locations, as knownto those of ordinary skill in the art. Currently, bond pads have about 4mils² surface area, although the present invention is not associatedwith any specific bond pad area, size or shape.

An electrically insulative, or dielectric, material 110 may be disposedon active surface 104 to enable physical attachment of semiconductor die100 by its active surface 104 to a second semiconductor substratecomponent in the form of another substrate. The dielectric material 110may be disposed over the entire active surface 104, except for a smallarea surrounding each of the bond pads 102, defining a cavity 106 overeach bond pad 102. The dielectric material 110 may comprise a layer ofmaterial applied in a flowable state, such as a thermoset resin in, forexample, the form of an epoxy, or it may be screen printed or stenciledto define cavities 106 as it is applied and optionally cured to a tackystate, or so-called “B-stage.” As with other semiconductor diefabrication processes, it is contemplated that such an application wouldbe effected to a semiconductor wafer, prior to singulation ofsemiconductor dice therefrom. Another approach is to spin coat a waferwith, for example, a polymer such as a polyimide, and then etch throughthe coating to expose bond pads 102. Further, dielectric material 110may be applied to active surface 104 as a preformed film of, forexample, polyimide (e.g., KAPTON® film), having apertures or vias 114preformed therein and coated on both sides with a suitable adhesive. Asyet another approach, a film of thermoplastic resin may be employed.

A second semiconductor component substrate 120, also termed a “carriersubstrate” herein solely for purposes of convenience and not limitation,is aligned with first semiconductor die 100 placed on the dielectricmaterial 110 and adhered to the semiconductor die 100 with dielectricmaterial 110 disposed therebetween. Second semiconductor componentsubstrate 120 may comprise an interposer or other carrier substrate suchas a printed circuit board formed, for example, as an FR-4 or a BT resinboard, a flexible tape such as a flexible adhesive-coated film, or anyother structure having a substantially planar region to whichsemiconductor die 100 is to be attached. Substrate 120 includes aplurality of second interconnect elements, such as terminal pads 122,conductive trace ends or other connective surfaces, arranged in apattern on surface 124 thereof corresponding to that of the array of thebond pads 102 of the semiconductor die 100. The terminal pads 122 mayeach have a surface area similar to that of the bond pads 102, or thesurface area may be somewhat larger or smaller than that of bond pads102. Surface 124 of second semiconductor substrate component 120 may beadhered to dielectric material 110 by the latter's own adhesivecharacteristics (in the case of a thermoset or thermoplastic resin) orby an adhesive coating thereon in the case of a preformed,adhesive-coated dielectric film. An intermediate semiconductor componentassembly 126 results.

Substantially closed interconnect voids 128 are formed between the bondpads 102 and the aligned terminal pads 122 in the regions of cavities106 in dielectric material 110, the dielectric material providing aspacing, or standoff, between semiconductor die 100 and carriersubstrate 120.

It will be appreciated, as depicted in FIG. 1A, that a perforateddielectric spacer element 112 may be placed between the semiconductordie 100 and the carrier substrate 120 in lieu of a layer of dielectricmaterial 110 to increase the vertical standoff therebetween and enhancethe volume of interconnect voids 128. Dielectric spacer element 112depicted in FIG. 1A may include apertures or vias 114 therethroughcorresponding in pattern to the patterns of the bond pads 102 andterminal pads 122. Dielectric spacer element 112 may be formed from anysuitable material, such as a substrate of semiconductor material withpassivated exterior surfaces, or a ceramic material. It maybe desirableto select a material exhibiting a coefficient of thermal expansion (CTE)similar to those of the semiconductor die 100 and carrier substrate 120,such as intermediate the CTEs of the latter two. The height, and thusvolume, of the interconnect voids 128 may thus be determined by thethickness of the dielectric spacer element 112 in combination with thelateral extent of the apertures vias 114. Dielectric spacer element 112may be coated with an adhesive layer 116 on each side thereof tofacilitate respective attachment to active surface 104 and connectivesurface 124. A semiconductor component assembly 126′ results. z

Turning to FIGS. 2 and 2A, an injection element in the form of injectionneedle 130 is inserted into each interconnect void 128. Injection needle130 has a bore 132 terminating in at least one opening 134 through whicha conductive material 140 maybe injected into the interconnect voids128. The at least one opening 134 maybe located at the tip 136 of theinjection needle 130 or may be located through needle sidewall 138opening into bore 132 (shown in broken lines), or may be a combinationthereof. Although the injection needle 130 depicted has a straight boreending in a conical tip, any configuration of a hollow tube that issuitable for insertion into the interconnect voids 128 and having aconductive material 140 passed therethrough may be used. Similarly,injection needle 130 may have any desired cross-sectional shape, whetherround, ovoid, polygonal or other. It may be advantageous to have the tip136 of injection needle 130 formed in a taper and having a sharp end,the reasons for which are set forth in greater detail below. Inaddition, and also as depicted in FIG. 2A, injection needle. 130 may beformed with a sharp tip 136 having at least one (two shown) laterallyextending cutting edge 136 ce.

In order to insert injection needle 130 into interconnect voids 128, itis necessary to penetrate the body of carrier substrate 120. In order toavoid the necessity of preperforating carrier substrate 120 under andthrough terminal pads 122, injection needle 130 may be formed with theaforementioned sharp tip 136 and punched through carrier substrate 120and terminal pads 122 a preselected travel into interconnect voids 128,forming injection aperture A through carrier substrate 120. The at leastone cutting edge 136 ce, by cutting a slit to the side of the main shaftof injection needle 130 behind tip 136, provides a vent aperture V toone or more sides of injection aperture A communicating betweeninterconnect void 128 and the exterior of carrier substrate 120.Furthermore, while injection needle 130 is depicted in an orientationperpendicular to carrier substrate 120 and punching through a terminalpad 122 as shown at the left-hand side of FIG. 2, it is contemplatedthat injection needle 130 may be inserted laterally offset to one sideand adjacent a terminal pad 122 but within the bounds of an interconnectvoid 128 as defined by dielectric material 110 or dielectric spacerelement 112 as shown in the center of FIG. 2 in broken lines. Likewise,injection needle 130 may be inserted at an acute angle to the plane ofcarrier substrate 120 to enter an interconnect void 128 without piercingor even contacting a terminal pad 122, as shown at the right-hand sideof FIG. 2.

After injection needle 130 is inserted into an interconnect void 128,conductive material 140 is injected, as depicted in FIG. 2. Apredetermined volume of the conductive material 140 is injected, suchvolume being calculated to substantially fill the interconnect void 128and adhere to bond pad 102 and aligned terminal pad 122 to form aconductive interconnect therebetween. If injection needle 130 is formedwith a tip 136 as illustrated, as the conductive material 140 isinjected into the interconnect void 128, air contained in theinterconnect void 128 and displaced by conductive material 140 exitsinterconnect void 128 through vent aperture V. Of course, if asufficiently thin and flexible material is employed for carriersubstrate 120, any trapped air may be displaced past the shaft ofinjection needle 130 without the need for cutting vent aperture V. Uponsolidification of conductive material 140, an operable semiconductorcomponent assembly 142 results (see FIG. 3). If conductive material 140is a molten solder, the characteristic substantially spherical solderball configuration may result, due to wettability of each aligned bondpad 102 and terminal pad 122 and surface tension of the molten solder.

Conductive material 140 may be any material that is suitably formulatedto be placed in a flowable state for injection into the interconnectvoid 128 and provide an electrical connection between the bond pad 102and terminal pad 122. For example, conductive material 140 may be aconductive polymer such as, but not limited to, a conductive epoxy, apolymer (again, without limitation, an epoxy) filled with conductiveparticles, a conductive paste, or a molten solder, such as a silver-,tin- or palladium-based solder. It is desirable that conductive material140 be formulated to wet and adhere to respective surfaces of bond pad102 and terminal pad 122. For example, where the conductive material 140is a molten solder, the bond pad 102 and terminal pad 122 may be fluxedto create a more wettable surface for adherence to the conductivematerial 140. The fluxing of the bond pad 102 and the terminal pad 122may occur prior to the attachment of the substrate 120 to thesemiconductor die 100. Of course, both the bond pad 102 and the terminalpad 122 may be covered with one or more layers of metal as are commonlyemployed in so-called “under-bump metallization” (UBM) structures onsemiconductor dice to facilitate the formation of solder balls thereon,as known to those of ordinary skill in the art.

Once a sufficient amount (which, as noted above, may be a predeterminedvolume) of conductive material 140 is injected to form a conductiveinterconnect 144 (see FIG. 3) across the interconnect void 128,injection is halted and the injection needle 130 is withdrawn. In someembodiments, needle withdrawal may be initiated before injection ceaseswhere appropriate, to allow any volume of the interconnect void 128taken by the injection needle 130 to be filled with conductive material140 as the injection needle 130 is withdrawn. Further, extension ofinjection needle tip 136 to a location immediately proximate a bond pad102 followed by controlled retraction of injection needle 130 may ensurebetter and more complete contact of conductive material 140 with bondpad 102 and terminal pad 122 over larger surface areas thereof.

Any required or desirable equipment or techniques for effectinginjection of conductive material 140 into interconnect void 128 may beused. For example, a metering pump may be used for pumping controlledvolumes of conductive material 140 to and through the injection needle130 into each interconnect void 128. Where the conductive material 140is a molten solder, a heated reservoir under temperature control may beused to melt solder pellets or a flux-containing paste and an injectionneedle 130 maintained at a controlled, elevated temperature may beemployed. Where the conductive material 140 is a conductive orconductor-filled two-part epoxy, separate resin and hardener reservoirsmay be employed to feed a mixing chamber via suitable pumps, and ametering pump may be used to feed injection needle 130. Of course, aplurality of injection needles 130 may be employed simultaneously. Forexample, a plurality of injection needles 130 of the same number as thenumber of interconnect voids 128 may be arranged in the same pattern sothat all interconnect voids 128 may be simultaneously filled.

It is also contemplated that the first and second semiconductorsubstrate components may be assembled together on a wafer scale ifsemiconductor dice 100 are to be matched, for example, to carriersubstrates in the form of interposer substrates. As used herein, theterm “wafer” is not limited to conventional wafers of silicon or othersemiconductor materials such as gallium arsenide and indium phosphidebut also includes bulk substrates including a layer of semiconductormaterial carried by a supporting structure including, withoutlimitation, silicon on insulator (SOI) substrates as exemplified bysilicon on glass (SOG) and silicon on sapphire (SOS) substrates, as wellas other structures known to those of ordinary skill in the art. Aftermutual assembly, injection of conductive material 140 may be effectedprior to singulation of the joined semiconductor dice 100 and carriersubstrates 120 by the use of ganged injection needles 130 extendingperpendicular to an injection head which is controlled to align in aplane parallel to the assembly with the terminal pads 122 of one or morecarrier substrates 120 and caused to extend injection needles 130 theaforementioned predetermined travel simultaneously into a plurality ofinterconnect voids 128, inject conductive material 140, withdraw fromthe assembly, translate to another desired location over the assembly,and repeat the aforementioned extension, injection and withdrawal. Ofcourse, as noted above, such a ganged needle injection approach may alsobe used when previously singulated semiconductor dice 100 have beenadhered to a surface 124 of any carrier substrate in the course offabrication, for example, of a multichip module such as a memory moduleor a motherboard.

As shown in FIG. 3, conductive interconnect 144 may fill substantiallythe entire volume of each interconnect void 128. This may beadvantageous in that the conductive interconnect 144 thus substantiallycovers the surface of bond pad 102 as well as the surface of opposingterminal pad 122, providing a superior electrical connection. Of course,it will be appreciated that the conductive interconnect 144 need notfill the entire volume of interconnect void 128, so long as the bond pad102 and terminal pad 122 are electrically connected therethrough.

According to the present invention, conductive interconnects 144 may beformed without the need for passing a semiconductor die 100 one or moretimes through a reflow oven, with consequent reduction in thermal stressduring fabrication and assembly, maintaining the integrity of the diceand increasing the life of the die and resulting semiconductor componentassembly.

In another embodiment of the present invention, access to eachinterconnect void 128 may be provided by a preformed injection port 150which passes through the substrate 120 into the interconnection space.Injection port 150 may be formed to pass through a terminal pad 122 asshown at the left-hand side of FIG. 4, or may enter the interconnectvoid 128 adjacent terminal pad 122 from a direction perpendicular to theplane of carrier substrate 120 as shown at the center of FIG. 4 or at anacute angle thereto, as shown at the right-hand side of FIG. 4.Injection port 150 may be formed during fabrication of carrier substrate120 or subsequently formed therein, as by mechanical drilling, etchingor laser ablation. In some embodiments, a vent port 152 may be formed inassociation with each interconnect void 128 for venting of displaced airtherefrom during injection of conductive material 140 (See FIG. 2).Although injection port 150 and vent port 152 are depicted as disposedin, and passing through, a carrier substrate 120, it is within the scopeof the present invention to provide such access ports through thesemiconductor die 100, provided that the ports may be formedtherethrough without affecting the circuitry of the semiconductor die100. It is further contemplated that an injection port 150 may beformed, for example, in a carrier substrate 120 while a vent portassociated with the same interconnect void 128 may be formed throughsemiconductor die 100, or vice versa.

Injection port 150 and vent port 152 (if present) may be formed in thecarrier substrate 120 or semiconductor die 100 using any suitabletechnique known to those of ordinary skill in the art. For example,these ports may be formed by drilling with a mechanical drill bit, bypunching, by laser ablation, by wet or dry etching, or as otherwisesuitable, given the selected material of the substrate being perforated.

Once conductive interconnect 144 is formed, injection aperture A orinjection port 150 and vent port 152 (if present) may be sealed, ifnecessary, to prevent contamination of the conductive interconnect 144or interconnect void 128 during subsequent processing or use of thesemiconductor component assembly, or shorting of the terminal pads 122by contact with conductors exterior to the assembly. A dielectricsealing material 154 may be applied over the injection aperture A asshown in FIG. 3, or the injection port 150 and vent ports 152 if presentto seal off the interconnect void 128 and, more specifically, anyresidual conductive material 140 which might remain and extend outwardlybeyond terminal pads 122 to or adjacent the exterior of carriersubstrate 120. Such residual conductive material 140 may occur due tooverfilling of an interconnect void 128 or through withdrawal ofinjection needle 130. The dielectric sealing material 154 may be anysuitable dielectric material, including flowable materials such asepoxies and polymers, thermoplastic films, or adhesive-coated films.

The dielectric sealing material 154 may be applied directly to fill aninjection aperture A or injection port 150 and vent port 152 in a volumethat occludes the opening to seal it, in a volume that fills the openingto a point beneath (recessed from) the surface 124 of the carriersubstrate 120, or in a volume that slightly overfills the opening tocreate a bump of the sealing material 154 on the surface 124 of thecarrier substrate 120. In some embodiments and as shown in broken linesin FIG. 3, the dielectric sealing material 154 may be applied as a layerof flowable material or film that covers either a portion of the exposedsurface 124 or the entire exposed surface 124 of the carrier substrate120. In such embodiments, the injection aperture A or injection port 150and vent port 152 are filled or at least occluded at the same time suchlayer is applied to or formed on the carrier substrate 120. On awafer-scale assembly, the dielectric sealing material 154 may be appliedto the center of the assembly and distributed thereover using spin-ontechniques.

In yet another embodiment of the present invention illustrated in FIG.5, an intermediate semiconductor component assembly 126 such as isillustrated in FIG. 1 further includes solder balls 160 preplaced incavities 106 prior to placement of carrier substrate 120 thereover.After assembly of intermediate semiconductor component assembly 126, anultrasonic head 200 is placed against carrier substrate 120 andactivated to vibrate and generate heat sufficient to at least partiallymelt solder balls 160 to bond to bond pads 102 and terminal pads 122. Itis also contemplated that pellets of a conductive or conductor-filledthermoplastic resin 160′ may be preplaced in cavities 106, andultrasonic head 200 employed to melt the resin to effect a connectionbetween bond pads 102 and terminal pads 122. It is also contemplatedthat a conductive paste, such as a solder paste, may be used. As shownin FIG. 5, ultrasonic head 200 may include protrusions 202 therefromarranged in the same pattern as bond pads 102 and terminal pads 122 sothat contact may be made at those locations to better focus theultrasonic energy, shorten heating time and avoid unnecessary heating ofother portions of the assembly.

It will be recognized and appreciated by those of ordinary skill in theart that details of the methods herein described may be variedconsiderably without departing from the scope of the invention asdefined by the claims which follow herein, and that additions, deletionsand modifications to the exemplary embodiments of the invention asdescribed may be made without departing from the scope thereof.

1. A method for electrically connecting semiconductor componentsubstrates, comprising: providing a first semiconductor componentsubstrate having at least one interconnect element on a surface thereofand an injection port extending therethrough; disposing a dielectricelement having at least one cavity therein on the surface of the firstsemiconductor component substrate, with the at least one cavity locatedover the at least one interconnect element; disposing a mass ofconductive material in the at least one cavity; providing a secondsemiconductor component substrate having at least another interconnectelement on a surface thereof; securing the second semiconductorcomponent substrate to the first semiconductor component substrate withthe dielectric element interposed therebetween and the at least anotherinterconnect element of the second semiconductor component substratealigned with the at least one cavity to form at least one interconnectvoid; and altering the mass of conductive material to a flowable stateto form at least one conductive interconnect structure within the atleast one interconnect void extending between the at least oneinterconnect element and the at least another interconnect element. 2.The method according to claim 1, further comprising selecting the massof conductive material from solder, a solder paste, conductivethermoplastic resin and conductor-filled thermoplastic resin.
 3. Themethod according to claim 1, further comprising heating the mass ofconductive material to alter it to the flowable state.
 4. The methodaccording to claim 3, further comprising heating the mass of conductivematerial using ultrasonic energy.
 5. The method according to claim 1,further comprising allowing the conductive material in the flowablestate to transform to a solid state in contact with the at least oneinterconnect element and the at least another interconnect element. 6.The method according to claim 1, further comprising selecting a volumefor the mass of conductive material to substantially fill the at leastone interconnect void.
 7. The method according to claim 1, whereinproviding a first semiconductor component substrate having at least oneinterconnect element on a surface thereof comprises providing asemiconductor die having at least one bond pad on a surface thereof. 8.The method according to claim 1, wherein providing a secondsemiconductor component substrate having at least another interconnectelement on a surface thereof comprises providing a carrier substratehaving at least one terminal pad on a surface thereof.
 9. The methodaccording to claim 1, wherein disposing a dielectric element on thesurface of the first semiconductor component substrate comprisesdisposing one of a flowable dielectric material and a preformeddielectric element on the surface of the first semiconductor componentsubstrate.
 10. The method according to claim 1, further comprisingselecting one of the first and second semiconductor component substratesto comprise a semiconductor die and selecting another of the first andsecond semiconductor component substrates to comprise a carriersubstrate.
 11. The method according to claim 1, further comprisingselecting a thickness for the dielectric element to at least in partdetermine a volume of the at least one interconnect void.
 12. The methodaccording to claim 1, wherein the at least one interconnect elementcomprises a plurality of interconnect elements, the at least anotherinterconnect element comprises a like plurality of another interconnectelements, and the at least one interconnect void comprises a likeplurality of interconnect voids therebetween.
 13. The method accordingto claim 12, further comprising simultaneously heating preformed massesof conductive material in the like plurality of interconnect voids. 14.The method according to claim 1, wherein disposing a mass of conductivematerial in the at least one cavity comprises injecting a flowableconductive material into the at least one interconnect void by insertingan injection needle through the injection port and into the at least oneinterconnect void.
 15. The method according to claim 1, whereindisposing a mass of conductive material in the at least one cavityoccurs after securing the second semiconductor component structure tothe first semiconductor component substrate.
 16. The method according toclaim 1, further including sealing the injection port after disposing amass of conductive material in the at least one cavity with a dielectricsealing material.
 17. The method according to claim 16, wherein sealingcomprises occluding the injection port.
 18. The method according toclaim 17, wherein occluding the injection port comprises disposing alayer of the dielectric sealing material over an exposed surface of theone of the first and second semiconductor component substrates.
 19. Themethod according to claim 1, further comprising providing the injectionport through an interconnect element.
 20. The method according to claim1, further comprising providing the injection port adjacent aninterconnect element.